Abstract : The membrane fusion is a common biological processes found in particular during exocytosis, intracellular trafficking or the entry of viruses into cells. As case of rhabdoviruses, a family where there are particular rabies virus RV and Vesicular stomatitis virus VSV, this function is ensured by slightly acidic pH glycoprotein G. This protein exists in at least three distinct conformations: at pH neutral, it is present in a native conformation N. After a brief incubation at pH acid, it is present in an active conformation A, under which it is capable interact with a target membrane via a hydrophobic peptide. Finally, after prolonged incubation at acidic pH, it appears as an inactivated conformation I and is then unable to induce membrane fusion. Unlike all the other families viruses studied to date, there is a balance between these pH-dependent conformations. Many data in various systems suggest that a single protein would not sufficient to catalyze the process of membrane fusion, but to a machinery consisting of more or less fusogenic protein is necessary. In this work, we studied some properties of the complex fusion rhabdoviruses. We have thus shown that it was large and that it was probably greater than had been proposed for other viral families. Moreover, it appeared the complex merger of rabies virus N was not a single architecture possible, but that there were rather different types of complex. Then, the observation by electron microscopy of viral particles in the process of merge with liposomes showed us that the process of fusion induced by VSV is always produced by the base and that he s accompanied with a complete rearrangement glycoproteins on the surface of the virus following a helical network. Finally, we are able to isolate the ectodomain of G and to obtain crystals diffracting to 3.5 Å, which allows to envisage a resolution of the structure of G. The study of the interaction between the ectodomain of G and liposomes allowed us to reproduce the observed helical networks on the surface of the virus and study their properties. The aggregate of these data allowed us to propose a new model for merger process among rhabdoviruses, but it could also be relevant for of other viral families.